Adjacent cells in a column using formulas have their data deleted

[endofhome]

I'm experiencing a problem where cells in a column have all their data deleted if two or more adjacent cells use formulas.

Here's the code:

require 'spreadsheet'
Spreadsheet.client_encoding = 'UTF-8'

def test

# open the spreadsheet
book = Spreadsheet.open 'test.xls'
sheet1 = book.worksheet 0

# the new data
a = 1
b = 2

# input the new data into the spreadsheet
sheet1[5, 1] = a
sheet1[5, 2] = b

# save to "-Modded" file in same folder. 
book.write 'test-Modded.xls'
end

test

The original file looks like this:

The result I want is this:

but the actual result is this:

test files, including an XLS file: https://www.dropbox.com/s/qblq7mcfy6cvc48/delete_error.zip?dl=0

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I should add that I'm using LibreOffice 4.4.4.3 to create and open the .XLS file. I don't have Excel on my system.

[zdavatz]

Ok, this looks like a bug. I will test and get back to you.

[zdavatz]

I get this, so I guess this is a bug. What Ruby Version are you using?

[zdavatz]

sorry, uploaded wrong screen.

[endofhome]

OK. Note the behaviour when the formula in D7 is moved down to D8 and D7 has no formula in it - everything then works as it should. The problem only appears when there are two adjacent formulas in a column.